dest_dir <- paste(Sys.getenv("tools_path"), "R", sep="/")
              install_local <- function(package) {
                      install.packages(package, dest_dir, repos=NULL)
              }
              install <- function(package) {
                      install.packages(package, dest_dir, destdir=dest_dir)
              }
              install_bio <- function(package) {
                      source("http://bioconductor.org/biocLite.R")
                      biocLite(package)
             } 
